Abstract

In order to explore the mechanism of temperature regulating fertility transformation in the thermo-sensitive male sterile of Chinese cabbage (TsCMS7311) (Brassica rapa L. ssp. pekinensis), the paper studied the related β-esterase isoenzymes from the gene expression. The β-esterase isoenzymes related to fertility changeover in TsCMS7311 were purified by one-dimensional and two-dimensional gel electrophoresis. Two polypeptides, whose molecular weights were 57.1 and 62 kD, were analyzed with Q-TOF mass spectrometry. We obtained three sequences of short peptides from the 57.1 kD polypeptide and two sequences of short peptides from the 62 kD polypeptide. The two short peptides sequences of 62 kD polypeptide were the same as that from the 57.1 kD polypeptide. This result indicated that the sequences of the two polypeptides were highly similar. By comparing the sequence with protein database of NCBI GenBank, it was found that the three short peptides were highly homologous (60 to 100%) to protein p27^SJ. This study would lay the theoretic foundation for the research of TsCMS7311.

Key words: Chinese cabbage, β-esterase isoenzymes, sequence analysis.